PubMed Health⌕ Search

Biomedical subjects

J A House

Publications and source records attributed to J A House.

At least 37 records · Page 2Linked to original sources
PubMed1993

Recommendations for African horse sickness vaccines for use in nonendemic areas.

African horse sickness (AHS), which causes mortality up to 95%, is caused by orbiviruses and is transmitted by Culicoides. The goal of a control and eradication program for AHS is to prevent the spread of the virus via the biological vector. Control measures include slaughter of infected animals, housing of suspected infected animals in insect-proof stalls, and vaccination. Vaccination has played a key role in eradication when AHS occurred outside of Africa. Both modified live vaccines (MLV) and inactivated vaccines have been used to control AHS. An acceptable vaccine should be: safe, efficacious, and available. The vaccine should not cause disease or viremia, and the vaccine virus should not revert to a virulent virus upon backpassage in susceptible Equidae. The vaccine should protect against death and clinical signs and, most importantly, should prevent viremia in vaccinated Equidae following exposure to virulent AHS virus. The challenge inoculation system for assessing immunity to AHS is discussed. The vaccine should be readily available, implying that it is either in routine production in facilities that meet internationally accepted guidelines for biological production facilities or in a vaccine bank. Banking of cryopreserved stocks of MLV or concentrates of inactivated vaccines is a means of having AHS vaccine available for future epizootics. A recently developed diagnostic test to differentiate vaccinated from naturally infected animals provides regulatory officials with useful information for the control of AHS.

African Horse Sickness↗
PubMed1991

Experimental equine herpesvirus-1 infection in llamas (Lama glama).

Three llamas (Lama glama) were experimentally infected intranasally with an isolate of equine herpesvirus-1 (EHV-1) from the brain of an alpaca that had experienced severe neurologic signs. Two of the 3 llamas developed severe neurologic disorders following inoculation; 1 died, and 1 was euthanized in a moribund state. The third llama showed only mild neurologic signs. The euthanized llama had preexisting antibodies to EHV-1, and the remaining 2 llamas were seronegative (virus neutralization titer less than 6) at the time of inoculation. One of the seronegative llamas died acutely without production of detectable antibodies, and the other developed antibodies typical of a primary immune response. The EHV-1 virus was recovered only from a sample of the thalamus of the llama that died acutely. Histopathologic lesions were observed in the brain and retina of the dead and euthanized animals. This study verifies the pathogenic potential of EHV-1 for llamas.

Animals↗
PubMed1990

Comparison of the effect of various chemical stabilizers and lyophilization cycles on the thermostability of a Vero cell-adapted rinderpest vaccine.

The thermostability of a rinderpest vaccine produced on Vero cells was evaluated using a variety of chemical stabilizers and lyophilization protocols. Three stabilizer preparations and three lyophilization schedules were examined using accelerated stability testing at 37 degrees C. The vaccine preparation exhibiting the greatest stability at 37 degrees C was tested at three additional temperatures, 42, 45 and 56 degrees C, and an Arrhenius plot was constructed from the data. The stability of the reconstituted vaccine produced with the two most efficacious stabilizers was examined using three different diluent preparations. The stabilization method and high Vero cell virus batch titers resulted in a lyophilized vaccine which maintained the minimum required dose of log10 2.5 TCID50 tissue culture infectious dose for more than 20 weeks at 37 degrees C.

Analysis of Variance↗
PubMed1990

The serological response to a thermostable Vero cell-adapted rinderpest vaccine under field conditions in Niger.

A lyophilized thermostable Vero cell-adapted ringerpest vaccine, stabilized with lactalbumin hydrolysate and sucrose, was tested for safety, serological response and suitability for use with an abbreviated cold chain under field conditions in Niger. A total of 480 cattle, 90 goats and 55 sheep of unknown serological status were vaccinated on government ranches and observed for at least 22 days. No untoward effects of the vaccine were detected. The serological response to the vaccine stored at environmental temperatures for 30 to 34 days was determined in 144 previously unvaccinated yearling calves. Seroconversion was demonstrated in 98% of the yearling calves using seroneutralization. The un-refrigerated vaccine retained a titer of 3.69 log10 TCID50 per dose through day 34.

Animals↗
PubMed1990

Inactivation of viral agents in bovine serum by gamma irradiation.

Cell culture origin or suckling mouse brain origin viruses of Akabane disease, Aino, bovine ephemeral fever, swine vesicular disease, hog cholera, bluetongue, and minute virus of mice were each suspended in bovine serum. Aliquots (1 mL) were exposed to various doses of gamma radiation from a 60Co source while at -68 degrees C. Aliquots (100-mL) of serum from a steer experimentally infected with foot-and-mouth disease virus were similarly irradiated. The samples were assayed for infectivity in cell culture systems before and after irradiation, and the data points were analyzed by linear regression. The irradiation doses (in megarads) necessary to inactivate one log10 of viral infectivity (D10) was calculated for each virus. D10 is otherwise known as the slope of the regression line. The r2 value, a measure of association with 1.0 = perfect fit, was also calculated for each regression line. The values (D10, r2) for each virus were as follows: Akabane, 0.25, 0.998; Aino, 0.35, 0.997; bovine ephemeral fever, 0.29, 0.961; swine vesicular disease, 0.50, 0.969; foot-and-mouth disease, 0.53, 0.978; hog cholera, 0.55, 0.974; bluetongue, 0.83, 0.958; and minute virus of mice, 1.07, 0.935.

Animals↗
PubMed1990

The isolation of lumpy skin disease virus and bovine herpesvirus-4 from cattle in Egypt.

Lumpy skin disease (LSD) virus (LSDV) was isolated for the first time from cattle in Egypt in 2 disease outbreaks. Bovine herpesvirus-4 (BHV-4) and LSDV were detected in a pooled sample from the first outbreak (Suez). Only LSDV was isolated from the second outbreak (Ismalia). The capripoxviruses were identified as LSDV by neutralization with specific antiserum and by their ability to produce generalized LSD in experimentally inoculated cattle.

Animals↗
PubMed1989

Evaluation of techniques to demonstrate foot-and-mouth disease virus in bovine tongue epithelium: comparison of the sensitivity of cattle, mice, primary cell cultures, cryopreserved cell cultures and established cell lines.

Tongue epithelia infected with each of the 7 serotypes of foot-and-mouth disease virus (FMDV) were used to evaluate in vivo and in vitro systems for the detection of FMDV. Cattle inoculated by the intradermal route in the tongue (IDL) and suckling mice inoculated intraperitoneally were compared for susceptibility to FMDV with freshly prepared bovine thyroid cell cultures; cultures from cryopreserved bovine thyroid, bone marrow, mammary gland, myocardium, tongue, ovary and kidney cells; cultures from cryopreserved embryonic ovine kidney, newborn ovine kidney, ovine testicle, bone marrow, and chloroid plexus cells; and the continuous porcine kidney cell lines MVPK-1 and S6. The mean titers determined for each serotype in each system were statistically compared. The FMDV titers obtained in freshly prepared bovine thyroid cell cultures and by cattle IDL inoculation were the highest and were statistically indistinguishable. The titers obtained by suckling mouse inoculation were significantly lower than the titers obtained in thyroid cultures for serotypes A, C, Asia 1, and SAT 3. The cattle IDL assay was significantly more sensitive than the mouse assay for serotype A. The cell cultures from the cryopreserved newborn ovine kidney and embryonic ovine kidney were significantly less susceptible to serotype Asia 1 when compared with the fresh bovine thyroid cultures, but not significantly different when compared with the cattle assay for all serotypes. Cryopreservation of bovine thyroid cells directly after trypsinization resulted in the loss of susceptibility to FMDV serotype SAT 2. The other cryopreserved cell culture systems exhibited no or minimal susceptibility to all 7 serotypes, or exhibited considerable inconsistency. The established cell lines MVPK-1 and S6 were not susceptible to serotype A, and were less sensitive to serotype C than other culture systems. Quality control of cell cultures used to evaluate field specimens for FMDV was critical. The cell cultures of cryopreserved ovine kidney cells provided the most practical diagnostic system.

Animals↗
PubMed1988

Characteristics of the porcine kidney cell line IB-RS-2 clone D10 (IB-RS-2 D10) which is free of hog cholera virus.

A Brazilian stock of clone C17 of the IB-RS-2 porcine kidney cell line which was contaminated with hog cholera virus (HCV) was cloned. One clone designated IB-RS-2 D10 was determined to be free of HCV, 20 other viruses, and Mycoplasma. IB-RS-2 D10 cells possessed the same viral susceptibility pattern as the contaminated parent cells to the viruses of foot-and-mouth disease, swine vesicular disease, vesicular exanthema of swine, transmissible gastroenteritis, and several other viruses. The IB-RS-2 D10 cells had a median chromosome count of 34, were morphologically epithelioid cells, and were resistant to HCV infection. Freedom from HCV affords advantages for vaccine production and avoids laboratory contamination.

Animals↗
PubMed1986

Susceptibility of various animals to the vesiculoviruses Isfahan and Chandipura.

To determine the pathogenic potential of the vesiculoviruses Isfahan and Chandipura for domestic animals, two ponies, two steers, three sheep, three goats and three pigs were inoculated with each virus intradermally in the tongue or, in the case of the pigs, in the snout, heel and coronary band. The ponies were also inoculated intradermally in the right commissure of the mouth. Animals inoculated with each virus were housed in one room and allowed to mingle freely with an equal number of uninoculated contact animals of each species. Clinical signs of infection, consisting of ulcers at the inoculation sites, were observed in the Chandipura study in two inoculated ponies, one inoculated steer and one inoculated goat. No elevated temperature was observed. Virus was isolated from the ulcerated tongue tissue, but not from serial blood samples, oesophageal-pharyngeal mucus samples, or from the tissues which were collected at necropsy. Precipitating antibody was not detected by the immunoelectroosmophoresis (IEOP) test in any of the pre- or post-serum samples except from two inoculated sheep at 29 days post-inoculation (D.P.I.). Low levels of neutralizing activity were detected in pre-inoculation serum from all steers, pigs, contact sheep, and one contact goat. By 15 D.P.I. all inoculated animals and contact ponies and steers exhibited increased neutralizing antibody titres. In studies with the Isfahan virus, lesions developed only at the inoculation sites in the two ponies, and the virus was isolated. No virus was isolated from any blood, oesophageal-pharyngeal mucus samples or tissues collected at necropsy. All pre-inoculation sera were negative for neutralizing and precipitating antibodies. By 14 D.P.I. all inoculated animals exhibited neutralizing antibody, while all the contacts remained negative. The IEOP test remained negative for all animals throughout the experiment. A sub-passage of a suspension of Isfahan-infected tongue tissue injected into ponies and steers also yielded only firm swellings of lesser extent than the original reaction at the inoculation sites. With both viruses, lethal infections were produced by intracranial or intraperitoneal inoculation of day-old mice and hamsters, and by allantoic inoculation of embryonating chicken eggs. Adult mice, hamsters, guinea-pigs and rabbits produced serum antibodies but lacked clinical signs.

Animals↗
PubMed1984

Susceptibility of various animals to the vesiculovirus Piry.

To determine the pathogenic potential of the vesiculovirus Piry for domestic animals, two ponies, two steers, three sheep, three goats and three pigs were inoculated intradermally in the tongue or, in the case of the pigs, in the snout, heel and coronary band. Inoculated animals were housed in one room and allowed to mingle freely with an equal number of uninoculated contact animals of each species. Clinical signs of infection, consisting of elevated temperature and ulcers at the inoculation sites, were only observed in the ponies, but all inoculated animals developed specific antibody following inoculation. In addition, one of the contact sheep had neutralizing antibody to Piry at 7 and 29 days post inoculation suggesting a contact infection. Virus was not demonstrated in tissues, other than tongue, of any animal. The failure of Piry virus to produce lesions in steers, sheep, goats and pigs and only limited ulcerations in ponies suggests that this virus is not similar pathogenically to New Jersey and Indiana strains of vesiculoviruses which produce classical vesicular stomatitis. Lethal infections were produced by inoculation into suckling mice and hamsters, adult hamsters and embryonating chicken eggs. Further, lethal infections followed contact of adult female hamsters with their inoculated litters.

Animals↗
PubMed1984

Development of an immunoelectroosmophoresis test for the detection and typing of antibodies to vesicular stomatitis viruses.

This study was conducted to develop a rapid test to detect type specific antibodies to various strains of vesicular stomatitis virus. Glycoprotein was extracted from purified vesicular stomatitis virus-Indiana 3 and used as antigen in an immunoelectroosmophoresis test (counter immunoelectrophoresis) to test reactivity with homologous hyperimmune serum and antisera to vesicular stomatitis virus-New Jersey, Indiana 1 and Indiana 2. A reaction was only detected with the homologous antiserum. A simpler preparation of antigen, a detergent extract of infected cells was also evaluated and shown to have less specificity in reactions with hyperimmune sera. This infected cell extract was, however, useful in detecting homologous antibodies in convalescent sera (natural vesicular stomatitis virus-New Jersey infection) and no reactions were detected with infected cell extracts of vesicular stomatitis virus-Indiana 1, 2 and 3.

Animals↗
PubMed1983

Isolation of bluetongue virus serotype 2 from cattle in Florida: serotype of bluetongue virus hitherto unrecognized in the Western Hemisphere.

A serotype of bluetongue virus (BTV) hitherto unrecognized in the Western Hemisphere was isolated from cattle in the United States. Clinical disease was not seen in the cattle which were part of a sentinel herd system in Florida designed for studying the epizootiology of BTV. The isolation of serotype 2 was the first recovery of a different serotype of BTV in the United States since 1967. At least 21 serotypes of BTV have been reported worldwide; the 5 serotypes of BTV now recognized in the United States are 2, 10, 11, 13, and 17.

Animals↗
PubMed1982

Antibodies to bluetongue viruses in animals imported into United States zoological gardens.

Three hundred forty-five serum samples from 30 zoological animal species which had been imported into the United States were examined retrospectively for the presence of antibody to bluetongue viruses. Ninety eight (28.4%) were positive for antibody to bluetongue group antigen by the bluetongue agar gel immunodiffusion test. Bluetongue antibodies, most of which were against serotypes exotic to the United States, were detected in 13 animal species from Africa not previously reported to be infected by bluetongue virus. The lack of virus neutralizing antibody to any of the 20 known bluetongue virus types in four of the 28 positive serums studied may indicate the existence of new bluetongue virus serotypes, cross reactions with other orbiviruses or a more rapid decline of neutralizing than precipitating antibody. The possibility of recrudescence of bluetongue virus infection from some inapparently infected zoological animals and existence of a known bluetongue vector (Culicoides variipennis) in the United States would suggest that further assessment of bluetongue in zoological animals be made.

Animals↗